Delayed-action auxiliary stitch cams

ABSTRACT

An auxiliary stitch cam is provided for use in combination with a main stitch cam in a circular knitting machine and is spaced from the main stitch cam by at least the distance between adjacent knitting needles. The main stitch cam is used to move all needles into stitch forming positions, whereas the auxiliary stitch cam is used to actuate only selected needles after they have moved through the space separating the main and auxiliary stitch cams such that yarn instead of being pulled from a supply spool as stitches are extended by the action of the auxiliary stitch cam are instead pulled from the loops of the stitches in the cloth being knitted.

United States Patent Mishcon DELAYED-ACTION AUXILIARY STITCH CAMS vInventor: Lester Mishcon, Miami Beach, Fla.

The Singer Company, New York, NY.

Apr. 28, 1972 Assignee:

Filed:

App]. No.:

US. Cl. 66/57, 66/54 Int. Cl. D04b 9/00, D04b 15/32 Field of Search66/57, 50, 54, 49

References Cited UNITED STATES, PATENTS Primary Examiner Ronald EeldbaumV Att0rney-William V. Ebs, Marshall J. Breen and Chester A. Williams,Jr.

[57] ABSTRACT An auxiliary stitch cam is provided for use in combinationwith a main stitch cam in a circular knitting machine and is spaced fromthe main stitch cam by at least the distance between adjacent knittingneedles. The main stitch cam is used to move all needles into stitchforming positions, whereas the auxiliary stitch cam is used to actuateonly selected needles after they have moved through the space separatingthe main and auxiliary stitch cams such that yarn instead of beingpulled from a supply spool as stitches are extended by the action of theauxiliary stitch cam are instead pulled from the loops of the stitchesin the cloth being knitted.

1 Claim, 4 Drawing [Figures DELAYED-ACTION AUXILIARY STITCH CAMSBACKGROUND OF THE INVENTION 1. Field of the Invention The inventionrelates to needle actuating camming for a circular knitting machine, andin particular to the use of a main stitch cam in combination with adelayed acting auxiliary stitch cam.

2. Description of the Prior Art It is known both in the case ofnon-jacquard and jacquard knitting machines to provide an auxiliarystitch cam which can be adjusted relative to a fixed main stitch cam tochange stitch length by causing more or less yarn to be pulled from ayarn supply spool as loops are formed. Examples of such use are shownand described, for example, in U. S. Pat. No. 3,614,877 for CompoundStitch Cam For Knitting Machines issued Oct. 26, 1971 to Jack Radin.

SUMMARY OF THE INVENTION In accordance with the invention, a main andauxiliary stitch cam are used to cause yarn to be drawn from formedloops in a fabric being produced rather than from a yarn supply spool,and in achieving such result the relative positions of the main andauxiliary stitch cam are critical, the required positions of the camsbeing that wherein the auxiliary stitch cam is circumferentiallyseparated from the main stitch cam in the direction of motion ofknitting needles relative to the cams by at least the distance betweenadjacent needles.

The main stitch cam is used to actuate all needles and form stitches ofa preselected length through the loops of a previous course of a fabricbeing knitted whereas the associated'auxiliary stitch cam is used toactuate only certain of the needles. By reason of the separation of theauxiliary stitch cam from the main stitch cam, the auxiliary stitch cambecomes effective as to any particular needle engageable with it toextend the loop on such needle only after the formation of a stitch onthe adjacent following needle by the main stitch cam. Because offriction between yarn of the stitch on the adjacent following needle andthe loop of the course through which such stitch is formed, when aneedle is pulled down by the auxiliary stitch cam it does not extend theloop thereon by drawing yarn from a yarn supply spool but instead drawsyarn from 'the adjacent loops to thereby lengthen the one loop andshorten the others.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagrammatic view illustratingthe principle of the invention.

FIG. 2 is a front elevational view of a cam section embodying theinvention.

FIG. 3 is a side view of the cam section of FIG. 2.

FIG. 4 is an exploded perspective view showing an auxiliary cam for thecam section of FIG. 2.

Referring to FIG. 1 of the drawing wherein the principle of theinvention is illustrated at one feed of a circular knitting machine,reference characters and 1 2 designate a main stitch cam and auxiliarystitch cam respectively. In order to practice the invention theauxiliary stitch cam must be separated from the main stitch cam in thedirection of motion of needles relative to the cams by at least thedistance between adjacent needles, and in FIG. 1 the minimum spacing 14is shown. It is also essential that all needles shall be drawn by themain stitch cam to a stitch forming position, whereas less than all befurther pulled down by an associated auxiliary stitch cam. In themachine taken by way of example for FIG. I, all needles, of which theneedles 16a through 16g are representative, are shown withcorrespondingly located upper butts 18a through 18g (provided to engagethe main stitch cam 10) and alternate needles are shown withcorrespondingly located lower butts 20b, 20d and 20f (provided to engagethe auxiliary stitch cam 12).

Yarn 22 constituting one feed of a machine is pulled into stitches 24through the loops 26 of an already formed course of a fabric by theaction of main stitch cam 10 on each of the needles. Such stitches 24formed by the main stitch cam are thereafter adjusted in length by theaction of the auxiliary stitch cam 12 on alternate needles. Because ofthe spacing 14 between the main and auxiliary stitch cam, when the:lower butt of an alternate needle initially engages the auxiliary stitchcam, the needle which follows in the direction of needle motion relativeto the cams has already been caused by the main stitch cam to complete astitch 24. Due to the presence of such stitch with its loop extendingthrough a loop of another course, it is more difficult as a needle isdrawn down by the auxiliary cam to pull yarn from a yarn supply spool 27than from the loops of the adjacent needles. As a needle is drawri downby the auxiliary stitch cam, yarn is therefore pulled from the loops ofthe adjacent needles rather than from the yarn spool. In this waystitches on alternate needles are lengthened to the size indicated forstitch 28 and stitches on the other needles are twice shortened first tothe size indicated for stitch 30 and then to the final size indicatedfor loop 32.

FIG. 2 shows one example ofa miulti-track needle actuating cam section34 having not only a main stitch cam 36, but also including auxiliarystitch cams 38 and 40 for use in accordance with the invention. As shownthe cam section includes adjustable cams 42, 44, 46 and 48. Such camsections are useful, for example in controlling the operation oftwo-butt knitting needles as 50a through 50d having correspondinglylocated butts 520 through 52d to engage the main stitch cam 36 and apreliminary raise cam 54, and having other butts 56, 58, 60 and 62engageable with the earns 42, 44, 46 and 48 respectively. An extensionof the preliminary raise cam 54 defines a guard cam 64 for all needlespreventing the uncontrolled downward flight of needles and a guard cam66 prevents the uncontrolled upward flight of needles.

The adjustable earns 42, 44, 46 and 48 are rotatably mounted anddisposable in knit, tuck or welt positions. As shown the earns 42, 44,46 and 48 are in the knit, tuck, knit and tuck positions respectively.In the welt position (not shown) an adjustable cam extends horizontally.Mechanism providing for the adjustability of the earns 42, 44, 46 and 48may be as shown "and described in my copending application for needleactuating camming for circular knitting machine Ser. No. 253,720 filedMay 16, 1972 or any other suitable mechanism may be utilized.

Side edge 68 of cam section 34 is provided with recesses 70, 72, 74 and76 in alignment with the rotatably adjustable earns 42, 44, 46 and 48respectively for receiving auxiliary stitch cam supporting members. Suchrecesses 70, 72, 74 and 76 include pins 78, 80, 82 and 84 respectivelyupon which auxiliary stitch cam supporting members may be pivotallymounted. The recesses also include threaded holes 86, 88, 90 and 92respectively for receiving holding screws by means of which an auxiliarystitch cam may be secured in a desired position in a recess. As shown,the cam section 34 includes an auxiliary stitch cam supporting member94, of which the auxiliary stitch cam 38 is a part, pivotally mounted ina recess 70 on pin 78, and includes auxiliary stitch cam supportingmember 96, of which the auxiliary stitch cam 40 is a part, pivotallymounted in recess 74 on pin 82. Holding screws 100 and 102 extendthrough holes in the auxiliary stitch cam supporting members such as thehole 98 shown in member 94 (FIG. 4) and further extend into the threadedholes in the recesses to maintain the members in place. The holes in theauxiliary stitch cam supporting members have substantially largerdiameters than the diameters of the screws extending through them asillustrated by the example of FIG. 4. The members may therefore betilted about their mounting pins to vertically adjust the position ofthe auxiliary stitch cams before the holding screws are tightened.

Preferably the main stitch cam 36 is adjustable and movable in adirection parallel to itself between a position wherein a stitch mayjust barely be formed by the action of the cam and a position whereinthe cam may be used to form an initial stitch of maximum desired length.The auxiliary stitch cams 38 and 40 are so located that they areseparated as indicated at 104, in the direction of motion of needlesrelative to the cam section 34, from the lower end of the main stitchcam by at least the spacing between adjacent needles when the mainstitch cam is in position to provide for the formation of an initialstitch of maximum length. ,With the auxiliary stitch cams so spaced fromthe main stitch cam, the auxiliary stitch cams may be used to relativelyadjust the length of stitches in a fabric which is being knitted (as inthe manner indicated for example in connection with the description ofFIG. 1) without pulling yarn from a yarn supply cone.

Reference character 106 designates a wing cam which is of the type shownand described in US. Pat. No. 3,457,736 forWing Cam for Pattern WheelKnitting Apparatus"issued July 29, 1969, and the back surface 108 ofwhich defines a restricted cam track of constant dimension with the mainstitch cam 36 for correspondingly located butts as 50a through 50d ofknitting needles, regardless of the position of the main stitch cam. Thewing cam is pivoted at 110 and spring biased as in the manner of thesaid US. Pat. No. 3,457,736.

One example of use of cam sections, such as the cam section 34, is inthe knitting of La Coste cloth. A La Coste pattern is readily knittedutilizing the needles shown in FIG. 2 repeated as often as requiredaround the cylinder of a machine to produce a desired width of thepattern, and actuating such needles with cam sets each of which includesa pair of cam sections 34 having adjustable cams disposed as shown inFIG. 2 followed by a pair of like cam sections wherein the first,second,

third and fourth rotatably adjustable cams under the guard cams aredisposed in the tuck, knit, tuck and knit positions respectively. Whenknitting the La Coste pattern those needles which are raised to the knitposition are actuated by the auxiliary stitch cams and such needles pullyarn from the tuck stitches and therefore have the desirable effect oftightening such tuck stitches in the cloth.

Patterns other than La Coste may be produced with the rotatablyadjustable cams of the cam section 34 positioned differently from thatindicated and with one or more auxiliary stitch cams utilized to tightenselected stitches and lengthen others. Also La Coste and other patternsmay be produced with cam sections which are constructed differently fromthe cam section 34 and which may or may not include a pattern wheel, butwhich makes use of one or more auxiliary stitch cams in accordance withthe invention. With adjustable main and auxiliary stitch cams it is ofcourse possible to alter differences in the size of loops produced inaccordance with the invention without changing the weight of yardage ofa particular amount of material producible on a machine. A particularfabric which may be conveniently produced making use of the invention istextured jersey the courses of which include stitches defined by longand short loops which alternate across the fabric. Another fabricconveniently produced making use of the invention is one havingsuccessive tucks in the same courses, an auxiliary stitch cam being usedto tighten the floated tuck loop.

While the invention has been described in its preferred form it is to beunderstood that the words which have been used are words of descriptionrather than of limitation, and that changes within the purview of theappended claims may be made without departing from the true scope andspirit of the invention.

Having thus set forth the nature of this invention, what is claimedherein is:

1. In combination, multi-butt knitting needles for a circular knittingmachine, each of the needles including a correspondingly located buttand at least one other butt; and needle actuating camming; said cammingincluding butt engaging cam means for raising needles to a yarnaccepting position, a main stitch cam which is adjustable in a directionparallel to itself and engageable with the correspondingly located buttsfor lowering all needles to a stitch forming position, and an auxiliarystitch cam which is adjustable in asubstantially vertical direction andis spaced from the main stitch cam in the direction of motion of theneedles relative to the camming such that when the main stitch cam ispositioned to form stitches of a maximum length, the main and auxiliarystitch cams are separated in the said direction by at least the distancebetween adjacent needles, said auxiliary stitch cams being engageablewith needle butts other than the needle butts engageable with the mainstitch cams for further lowering selected needles to relatively adjustthe length of fabric loops utilizing only yarn in stitches alreadyformed.

1. In combination, multi-butt knitting needles for a circular knittingmachine, each of the needles including a correspondingly located buttand at least one other butt; and needle actuating camming; said cammingincluding butt engaging cam means for raising needles to a yarnaccepting position, a main stitch cam which is adjustable in a directionparallel to itself and engageable with the correspondingly located buttsfor lowering all needles to a stitch forming position, and an auxiliarystitch cam which is adjustable in a substantially vertical direction andis spaced from the main stitch cam in the direction of motion of theneedles relative to the camming such that when the main stitch cam ispositioned to form stitches of a maximum length, the main and auxiliarystitch cams are separated in the said direction by at least the distancebetween adjacent needles, said auxiliary stitch cams being engageablewith needle butts other than the needle butts engageable with the mainstitch cams for further lowering selected needles to relatively adjustthe length of fabric loops utilizing only yarn in stitches alreadyformed.